CN114514006A - Device and method for advancing a catheter or other medical device through a lumen - Google Patents

Abstract

Devices, systems, and methods are disclosed that facilitate delivery of an external catheter or other medical device to a location within a patient's body. The apparatus includes a conveyor catheter configured to be positioned in a lumen of an external catheter, the conveyor catheter including a shaft, at least one orienting balloon positioned on the shaft adjacent a distal end of the shaft and configured to slidably engage an inner surface of a vasculature of a patient, and at least one anchoring balloon positioned on the shaft between the orienting balloon and a proximal end of the shaft, the anchoring balloon configured to non-slidably anchor the conveyor catheter to the external catheter, and the conveyor catheter configured to be pushed and/or twisted to advance and steer the external catheter through the vasculature of the patient.

Description

Device and method for advancing a catheter or other medical device through a lumen

Cross Reference to Related Applications

This application is a partial continuation application of co-pending U.S. patent application No. 16/721,909 filed on 19.12.2019 and claiming the benefit of U.S. provisional application No. 62/886349 filed on 14.8.2019, wherein U.S. patent application No. 16/721,909 is a partial continuation application of co-pending U.S. patent application No. 16/701,966 filed on 3.12.2019; the entire contents of the above application are incorporated herein by reference.

Technical Field

The present invention relates generally to devices, systems, and methods that facilitate delivery of a catheter or other medical device to a location within a patient's body. More particularly, the present invention relates to a delivery catheter that is positioned within an external catheter (e.g., sheath), introducer catheter, guide catheter, or internal catheter. The orienting balloon at the tip of the conveyor catheter facilitates orientation and positioning of the conveyor catheter, and the anchoring balloon serves to anchor the conveyor catheter, for example, to the inner surface of a sheath or introducer catheter or guide catheter or internal catheter, as the user maneuvers the system comprising the conveyor catheter and the sheath or introducer catheter or guide catheter through the patient's body.

Background

Catheters are used for an increasing number of medical procedures, including diagnostic and/or therapeutic procedures. To facilitate placement of the diagnostic and/or therapeutic catheter at a location of interest within a patient, the catheter may be introduced through a second catheter, which is commonly referred to as a "sheath" or "introducer catheter," and these two terms will be used interchangeably herein. An introducer catheter is a tube used to facilitate placement of other catheters into specific areas of a patient's body. For example, in the field of cardiac ablation, an introducer catheter may be used to navigate a patient's vasculature so that an ablation device may be passed and positioned to ablate cardiac tissue causing arrhythmias. The introducer catheter itself may be advanced over the guidewire.

The complex coronary anatomy (including distortion, calcification and other structural features of the coronary arteries) can make hardware difficult, and sometimes even impossible, to transport through the lumen proximal to the stenosis. Several advances in technology (e.g., stiffer guidewires, large-caliber guide catheters that allow for improved passive support, and hydrophilic coatings that provide reduced friction) have improved the ability to advance balloons and stents through these coronary arteries with some success. A guidewire that allows dynamic deflection of the tip, such as a twisted wire, also improves hardware delivery. However, even with these advances, the need to improve the outcome of percutaneous coronary intervention ("PCI") in complex matrices has not been met in view of the ever-expanding indications for PCI.

The guide catheter may be located inside the introducer catheter, with an internal support catheter (a "sub" catheter or "pediatric" catheter) placed inside the guide catheter. Advancing an internal support catheter into the coronary artery to deeply cannulate the proximal coronary artery lumen has been shown to improve the support of the guide catheter and internal catheter composite system, providing an opportunity for success in advancing the device through the refractory coronary artery lumen (Guideliner extension catheter, Guidezilla extension catheter, speculum). Typically, these internal catheters can only be navigated in the proximal, simpler part of the arterial anatomy, and do not allow the operator to obtain a position in the arterial lumen that provides adequate support for the guide catheter and internal catheter complex. The inability to advance these internal catheters further into the patient's vasculature is often due to a "razor effect" caused by the overhang or transition between the guide wire and the internal support catheter.

Generally, the overall diameter of known introducer catheters must be small enough to pass through the lumen of a blood vessel, while retaining a large enough internal diameter (or "bore") to accommodate diagnostic, therapeutic and/or ablation devices therethrough. Furthermore, since the path within the patient's vessel is typically long and tortuous, steering forces must be transmitted over relatively long distances. Accordingly, it is desirable that the introducer catheter have sufficient axial strength to be pushed through the patient's vasculature via a force applied at its proximal end ("pushability"). It is also desirable for the introducer catheter to be able to transmit torque applied at the proximal end to the distal end ("torqueability"). The introducer catheter should also be sufficiently flexible to substantially conform to the vasculature of the patient and resist kinking as it conforms to the vasculature of the patient. These different features often conflict with each other, and improvements in one often require compromises in the other. For example, increasing the pore size of an introducer catheter having a given overall diameter requires the use of thinner walls. As catheters are used in smaller and smaller passages and vessels, there is an increasing need to use introducer catheters having smaller outer dimensions. However, thin-walled introducer catheters are more likely to collapse or kink on their own when torque or thrust is applied at their proximal ends.

To facilitate advancement of the introducer catheter (or introducer sheath) through the patient's vasculature, the ability to apply a pushing force and/or torque at the proximal end of the introducer catheter and selectively orient the distal tip of the introducer catheter in a desired direction may allow medical personnel to advance the distal end of the catheter and position the distal portion of the introducer catheter at a location of interest.

During use, the introducer catheter shaft should be capable of transmitting torque and resisting compression. The high friction forces sometimes resist the transmission of axial forces and torque along the length of the introducer catheter. In some cases, these forces may cause the introducer catheter shaft to twist about the longitudinal axis of the introducer catheter shaft, storing energy in a spring-like manner during this process. If this energy is suddenly released, the distal end of the introducer catheter, which may have been deflected by the steering mechanism, may be undesirably driven with significant force.

With respect to resistance to compression during use, it is important that the user be able to advance the introducer catheter through the blood vessel, sometimes against significant frictional resistance, without excessive axial or radial compression or snaking or fishmouth shape of the introducer catheter shaft. Shaft compression can complicate positioning the distal end of the introducer catheter shaft at the desired location for the medical procedure. In addition, medical personnel may rely on tactile feedback to obtain and verify proper positioning of the introducer catheter, which may be compromised by excessive compressibility.

Accordingly, there is a need for improved devices, systems, and methods to deliver an introducer catheter or sheath or guiding catheter or internal catheter through a body lumen at a location of interest within a patient's body without damaging the lumen or body vessel (including tortuous lumens or vessels). The foregoing discussion is intended to be merely illustrative of the art and should not be taken as negating or limiting the scope of the claims.

Disclosure of Invention

Devices, systems, and methods for facilitating the passage of a patient's vasculature through a lumen or vessel are described herein. In particular, the present invention provides improved devices, systems and methods for procedures including diagnostic, therapeutic and ablation procedures in arterial and venous systems, as well as for non-vascular lumens and vessels. The catheter system of the present invention includes a conveyor catheter and an introducer catheter. In an exemplary embodiment, a balloon located at the distal tip of the conveyor catheter facilitates smooth passage of the conveyor catheter and/or associated device or system through the body lumen of the patient. The conveyor catheter may have at least one anchoring balloon that anchors the conveyor catheter to the introducer catheter. When the orienting balloon of the conveyor catheter experiences increased resistance within the vasculature of the patient, the anchoring balloon partially or completely prevents the conveyor catheter from sliding or "pushing" back into the lumen of the introducer catheter. Also, when the anchoring balloon is positioned proximate to the orienting balloon, the anchoring balloon acts as a stop to prevent the orienting balloon from backing into the lumen of the introducer catheter as the catheter system is maneuvered through the vasculature of the patient's body. It may also prevent the orienting balloon from moving completely out of the introducer catheter, guide catheter or internal catheter when a forward force is applied to the catheter system. In the description of the present invention, the conveyor conduit is described as being located within the introducer conduit. The transporter catheter may also be positioned within any external catheter (e.g., a sheath, parent catheter, guide catheter, or child catheter) to advance the external catheter. An orienting balloon at the tip of the conveyor catheter assists in the orientation and positioning of the conveyor catheter, while an anchoring balloon is used to anchor the conveyor catheter, e.g., to the inner surface of the outer catheter, as the user maneuvers the system comprising the conveyor catheter and the outer catheter through the vasculature of the patient. The description and discussion regarding advancing the introducer catheter also applies to using the transporter catheter to advance any other external catheter through the vasculature of a patient.

The catheter system of the present invention may be advanced through the vasculature of a patient's body by (a) pushing and/or twisting an introducer catheter, (b) pushing and/or twisting a conveyor catheter, or (c) both pushing and/or twisting an introducer catheter and a conveyor catheter. If the user pushes and/or twists the introducer catheter to advance the catheter system through the vasculature of the patient's body, the anchor balloon of the transporter catheter pushes and/or twists the transporter catheter as the catheter system moves through the vasculature of the patient's body. If the user pushes and/or twists the transporter catheter to advance the catheter system through the vasculature of the patient's body, the anchoring balloon of the transporter catheter pulls and/or twists the introducer catheter as the catheter system moves through the vasculature of the patient's body. In both cases, the orienting balloon helps orient and steer the catheter system through the vasculature of the patient's body.

One embodiment of the present invention provides devices, systems, and methods comprising a conveyor conduit comprising: a first tube having a length and defining a first open interior lumen connected to a first balloon at a distal end of a conveyor catheter; a second tube having a length and defining a second open interior lumen connected to a second balloon located between the first balloon and the proximal end of the conveyor catheter. In another embodiment, the second balloon is adjacent to the first balloon. In yet another embodiment, the distance between the proximal end of the first balloon and the distal end of the second balloon is less than half the length of the fully inflated first balloon. In another embodiment, the distance between the proximal end of the first balloon and the distal end of the second balloon is less than half the diameter of the fully inflated first balloon. In one embodiment, the length of the orienting balloon is in the range of 15-40 mm. In another embodiment, the directional balloon expands to a diameter in the range of 1.5-6mm after inflation. In yet another embodiment, the directional balloon expands to a diameter in the range of 6-12mm when inflated.

In one embodiment of the invention, the apparatus includes a conveyor catheter having a proximal end and a distal end, at least one first balloon at the distal end substantially at the tip of the conveyor catheter, and at least one second balloon between the distal end and the proximal end of the conveyor catheter. The first balloon is a directional balloon and the second balloon is an anchoring balloon. The conveyor catheter may include a single lumen or more than one lumen. In one embodiment, the shaft of the delivery catheter may be made of a polymer, such as Polytetrafluoroethylene (PTFE) or PEBAX (polyether block amide). In another embodiment, the shaft of the conveyor catheter may include a wire-based reinforcement embedded in a polymer shaft. In another embodiment, the shaft of the conveyor conduit may comprise an inner layer and an outer layer. In one embodiment, the inner layer may be made of a material that is more flexible than the material of the outer layer. In another embodiment, the outer layer comprises a material having a lower flexural modulus and a higher yield strain than the material of the inner layer. In one embodiment, the outer layer may include a braided wire assembly formed by braiding a plurality of flat or round wires. The shaft of the conveyor conduit may comprise a plurality of segments having different stiffness characteristics. A first section of the conveyor catheter having an axis between the orienting balloon and the anchoring balloon may have a stiffness that is less than a stiffness of a second section of the shaft between the anchoring balloon and the proximal end of the catheter. In another embodiment, the stiffness of the portion of the first section of the shaft proximal to the orienting balloon may be less than the stiffness of the portion of the first section of the shaft proximal to the anchoring balloon.

Another embodiment of the present invention provides devices, systems, and methods that include an introducer catheter having the ability to be steered through the vasculature of a patient's body independently of a transporter catheter. Such introducer catheters are commonly referred to as "steerable guide" catheters. One embodiment of the steerable guide catheter includes at least a first handle assembly including a first deflection mechanism coupled to the distal portion of the steerable guide catheter to apply a deflection force to bend the distal portion, and a second deflection mechanism coupled to the distal portion of the steerable guide catheter to apply a deflection force to bend the distal portion to a first articulated position, and adapted to bend the distal portion to a second articulated position. The steerable guide catheter also includes at least one open interior lumen to accommodate passage of the conveyor catheter to aid in the orientation and positioning of the steerable catheter. A conveyor catheter located within the steerable guide catheter assists in orienting and positioning the steerable catheter and supplements the function of the deflection mechanism to smoothly advance the steerable catheter. After positioning the steerable guide catheter at the desired location, the orienting and anchoring balloons in the conveyor catheter are deflated and the conveyor catheter is removed from the inner lumen of the steerable guide catheter.

Drawings

FIG. 1 is a perspective view of a conveyor conduit according to one embodiment of the invention.

FIG. 2 is a perspective view of the conveyor conduit with a first section of the conveyor conduit being more flexible than a second section of the conveyor conduit.

Fig. 3 is a perspective view of a conveyor conduit containing multiple sections of conveyor conduit with multiple degrees of flexibility (multiple degrees of flexibility/flexibilities).

Fig. 4a is a perspective view of a conveyor catheter showing a contoured directional balloon that promotes smooth movement of the directional balloon by reducing drag.

Fig. 4b is a perspective view of the conveyor catheter showing the perfusion lumen perfusing blood through the anchoring balloon when the anchoring balloon is inflated.

Fig. 4c is a perspective view of the conveyor catheter showing the perfusion lumen perfusing blood through the orienting balloon when the orienting balloon is inflated.

Fig. 5 is a perspective view of a conveyor catheter with more than one anchoring balloon.

Fig. 6 is a perspective view of a conveyor catheter having multiple segments of different stiffness with an anchoring balloon present on more than one segment.

FIG. 7 is a perspective view of a conveyor conduit having a hydraulic system to propel the conveyor conduit.

Fig. 8 a-8 d are perspective views of modifying the surface of the anchoring balloon to enhance anchoring to the inner surface of the introducer catheter.

Figure 9 is a perspective view of a catheter system including a carrier catheter and an introducer catheter advanced through the vasculature of a patient's body.

Fig. 10 a-10 b are schematic views of the forces acting on the introducer catheter wall when the introducer catheter is pushed at its proximal end or pulled at its distal end.

FIG. 11 is a perspective view of a catheter system including a parent catheter, an internal support catheter, and a conveyor catheter being advanced through a lumen of a disadvantaged artery.

FIG. 12 is a perspective view of a catheter system including a parent catheter, an internal support catheter, and a transporter catheter that has been advanced through a lumen of an unfavorable artery.

FIG. 13 is a perspective view of a stent positioned in an adverse arterial lumen using a catheter system comprising a parent catheter, an internal support catheter, and a transporter catheter.

Fig. 14 a-14 d are perspective views of the surface of the proximal portion of the balloon modified to enhance anchoring of the proximal portion of the balloon to the inner surface of the introducer catheter.

Fig. 15 is a perspective view of a conveyor catheter having a balloon with a surface at a distal portion thereof configured to move smoothly through a patient's vasculature and a surface at a proximal portion thereof configured to anchor to an external catheter.

FIG. 16 is a perspective view of a conveyor catheter with a balloon having a distal portion with a diameter that is larger than the outer diameter of the outer catheter when inflated.

Fig. 17 is a perspective view of a conveyor catheter having two balloons, a first balloon at a surface of a distal portion thereof configured to move smoothly through a patient's vasculature and a surface at a proximal portion thereof configured to anchor to an external catheter, while a second balloon is used to additionally anchor to the external catheter.

FIGS. 18 a-18 d are perspective cross-sectional views of the shaft of some embodiments of the conveyor conduit.

FIG. 19 is a perspective cross-sectional view of the distal portion of an embodiment of a conveyor catheter that can use wire-pull steering.

Detailed Description

Embodiments of the present invention are described below with reference to the drawings. The system using the conveyor catheter according to the invention provides improved steerability, flexibility and kink resistance.

Referring to fig. 1, catheter 100 includes a shaft 101 having a proximal end 102 and a distal end 103, and a first lumen 104, a second lumen 105, and a third lumen 106. First lumen 104 extends substantially the entire length of shaft 101 and communicates with a directional balloon 107 located near distal end 103 of shaft 101. The second lumen 105 extends the entire length of the shaft 101 and allows the catheter 100 to be placed over a guidewire 108. The third lumen 106 is in communication with an anchoring balloon 109, the anchoring balloon 109 being located between the orienting balloon 107 and the proximal end 102 of the shaft 101. In one embodiment, the anchoring balloon is positioned proximal to the orienting balloon. In another embodiment, the first lumen 104 and the third lumen 106 are diametrically opposed, and each lumen extends substantially parallel to the longitudinal axis of the shaft 101. In another embodiment, the first lumen 104 and the third lumen 106 are symmetrically disposed on either side of a longitudinally extending plane bisecting the axis into a first semi-cylindrical portion and a second semi-cylindrical portion.

In another embodiment, the third lumen 106 in communication with the anchoring balloon may be adapted to receive a removable stiffening stylet to facilitate insertion through the stiffening catheter shaft. In yet another embodiment, two removable stiffening stylets may be inserted, one into lumen 104 and the other into lumen 106. The stiffening stylet(s) is inserted to extend substantially the entire length of the member 101 until just proximal to the anchoring balloon 109. If two stylets are used, the practitioner may insert one stylet into a more distant position than the other to adjust the stiffness metric as needed. In one embodiment, the stylet is not inserted beyond the anchoring balloon.

Lumens 104, 105, and 106 are attached at their proximal ends to luer connector 111. The luer connector is then connected to a syringe, valve, or the like to provide for the introduction of a balloon inflation medium. In one embodiment, radiopaque markers may be positioned along the shaft 101 (including the distal end 103). In another embodiment, radiopaque markers may be located on the anchoring balloon 109. In one embodiment, the imaging marker is fixed to shaft 101 at its distal end portion, disposed slightly proximal to tip 103 and in the region near the forward end portion of orienting balloon 107. In another embodiment, the imaging marker is affixed to the orienting balloon 107. In yet another embodiment, the imaging marker is fixed to the anchoring balloon 109. In one embodiment, the imaging marker is formed from a radiopaque material (e.g., gold, platinum, tungsten, or alloys of these metals or from a silver-palladium alloy or a platinum-iridium alloy). By doing so, the position of the catheter can be confirmed, and the catheter 100 then advanced through the patient's vasculature while monitoring such advancement using radiographic imaging and visualization. In one embodiment, the shaft of the transporter catheter may have a lumen from its proximal end to its distal end for injecting the drug at the distal end by using a luer connector at the proximal end.

The mechanical properties of the segments of the shaft 101 may be varied by adjusting and changing the properties of the cylindrical braided structure(s) and the polymeric material (e.g., the dimensions of the cylindrical braided structure and/or the stiffness of the polymer). Furthermore, the mechanical properties of the segments of the shaft 101 may vary along the length of the shaft 101 according to certain embodiments of the present disclosure, or may be substantially uniform along the entire length of the shaft 101 according to other embodiments of the present disclosure. In another embodiment, shaft 101 is a unitary elongated tubular shaft member having an inner core made of a first material and an outer layer made of a second material, the first material of the inner core defining lumens 104, 105, and 106 therein, the cross-sectional dimension of first lumen 104 being uniform along the length of first lumen 104, the cross-sectional dimension of second lumen 105 being uniform along the length of second lumen 105, and the cross-sectional dimension of third lumen 106 being uniform along the length of third lumen 106. In one embodiment, the tubular shaft member has an outer cross-sectional dimension that varies along the length of the tubular shaft member, the outer cross-sectional dimension being greater at the proximal end than at the distal end.

In one embodiment, the shaft 101 may be provided with a rigidity imparting structure. In one embodiment, a blade is used to provide the rigidity-imparting structure. The blade may be formed of a metal wire or a synthetic resin wire. In another embodiment, as shown in fig. 2, the shaft is provided with a rigidity-imparting structure throughout its length 201, except for the distal portion 202 of the shaft from the anchoring balloon 209 to the orienting balloon 207. Anchoring balloon 209 anchors the rigidity-imparting structure 201 to the inner surface of the lumen of introducer catheter 224. In another embodiment, the rigidity-imparting structure is provided to the shaft 101 in a range from the proximal end 102 of the conveyor catheter to the distal end 115 of the anchoring balloon 109. In one embodiment, the shaft of the conveyor conduit is rigid and kink resistant. In another embodiment, the shaft of the conveyor catheter comprises an inner layer preferably made of a lubricious material, such as Polytetrafluoroethylene (PTFE), and an outer layer preferably made of a thermoplastic elastomer, such as PEBAX (polyether block amide). In another embodiment, the inner and outer layers are made of two different melt processable polymers. In another embodiment, the shaft of the conveyor conduit may comprise more than two layers. In another embodiment, the inner and/or outer layers include particulate radiopaque filler material. In another embodiment, the outer surface of the shaft of the transporter catheter may have at least one radiopaque band along the length of the shaft and/or radiopaque markers at specific locations of the shaft (e.g., at the distal end of the transporter catheter).

In one embodiment, the wire-based reinforcement is embedded in the outer layer. The wire-based reinforcement may be in the form of a braided matrix or a helical coil. The braided matrix may be woven. The braided matrix layer or the helical coil layer may be bonded to the inner layer, for example by melting in place. In one embodiment, the braided matrix layer or helical coil layer is bonded to the inner layer by melting in place using a temporary shrink tube as the forming member. The braided matrix layer or helical coil layer may also be referred to as a torque transfer layer. In another embodiment, the shaft includes a plurality of sections having wire reinforcements in the form of braided matrices or helical coil layers extending continuously from the proximal end 102 of the shaft along at least one length. In another embodiment, the shaft comprises multiple sections, wherein a braided matrix layer or helical coil layer extends continuously from the proximal end 102 of the shaft to the distal end 115 of the anchoring balloon 109. In another embodiment, the shaft comprises multiple sections, wherein a braided matrix layer or helical coil layer extends continuously from the proximal end 102 of the shaft to the proximal end of the orienting balloon 107.

The braided matrix or helical coil may be made of round wire, oval wire, flat wire, or combinations thereof. Any other cross-sectional shape of the wire may also be used. The filaments may be made of a variety of materials and may each be made of the same material or materials with similar material properties or of different materials with different properties. By way of example, such wires may be formed of stainless steel. The material of the filaments may be harder than the plastic material forming the shaft wall. In one embodiment, the flat wire is at least about 0.003 "(inches) thick and about 0.007" wide. In another embodiment, the filaments may be made of nitinol. In one embodiment, the braided wire plait matrix has a proximal portion and a distal portion, the braided wire plait matrix having a first density at the proximal portion and a second density at the distal portion, and wherein the first density is different than the second density, the density of the braided wire assembly measured in units of pixels per inch of braided wire (PPI) of the longitudinal axis of the shaft. In another embodiment, the PPI of the proximal portion of the braided wire matrix is greater than the PPI of the distal portion of the braided wire matrix. In another embodiment, the PPI is between about 10 and about 90. In yet another embodiment, the PPI is between about 5 and about 50. In another embodiment, the shaft of the conveyor catheter comprises a braided wire matrix, wherein the PPI gradually changes from the proximal portion to the distal portion of the shaft, whereby the stiffness of the shaft gradually decreases from the proximal portion to the distal portion. In another embodiment, the braided wire matrix is wrapped around the inner layer of the shaft. In another embodiment, a helical coil of wire is wound around the inner layer of the shaft. In yet another embodiment, the pitch of the helical coil at the proximal portion of the shaft is less than the pitch of the helical coil at the distal portion of the shaft. In another embodiment, the shaft of the transporter catheter comprises a helical coil of wire, wherein the pitch of the thread progressively increases from the proximal portion to the distal portion of the shaft, whereby the stiffness of the shaft progressively decreases from the proximal portion to the distal portion.

The torque transfer layer may be made of stainless steel (304 or 316) wire or other acceptable materials known to those of ordinary skill in the art. In one embodiment, the torque transmitting layer is formed from a braided wire assembly comprising flat wires, preferably stainless steel wires, including, for example, high strength stainless steel wires. The torque transmitting layer may be formed in any combination of weave patterns, including a crossed pattern of one over one (involving at least two filaments) or two over two (including at least four filaments). In one embodiment, the torque transmitting layer may be constructed with varying braid densities along the length of the conveyor conduit. For example, the torque transfer layer may be characterized by a first braid density at the proximal end of the carrier catheter, and then transition to one or more braid densities as the torque transfer layer approaches the distal end of the carrier catheter. The braid density at the distal end may be greater or less than the braid density at the proximal end. In one embodiment, the braid density at the proximal end is about 50PPI and the braid density at the distal end is about 10 PPI. In another embodiment, the braid density at the distal end is about 20-35% of the braid density at the proximal end. The torque transmitting layer may be formed separately on the disposable core and then slipped around the liner. One or more portions of the torque transfer layer may be thermally tempered and cooled prior to being bonded to the conveyor shaft by methods known to those of ordinary skill. The effect of the thermal tempering may help relieve stress on the wire and help reduce radial forces. In another embodiment, the torque transmitting layer may be woven directly onto the liner. In yet another embodiment, the torque transfer layer may comprise at least one helical coil of steel wire. The distance between two consecutive spirals of the helical coil, referred to as the pitch, may vary along the length of the conveyor conduit. For example, the torque transfer layer may be characterized by a first pitch of the helical coil at the proximal end of the carrier catheter, and then transition to one or more pitches as the torque transfer layer approaches the distal end of the carrier catheter. The pitch of the helical coil at the distal end may be greater or less than the pitch of the helical coil at the proximal end. In one embodiment, the pitch at the distal end is about 50-80% greater than the pitch at the proximal end.

In another embodiment of the invention shown in fig. 3, the shaft has a first flexible portion 301 arranged at the distal end of the shaft, a second flexible portion 302 continuous with the first flexible portion 301 and having flexibility/flexibility but a higher durometer than the first flexible portion 301, and a third flexible portion 303 continuous with the second flexible portion 302 and having a higher durometer than the second flexible portion 302. In the embodiment shown in fig. 3, the most flexible first flexible portion 301 is located between the orienting balloon 307 and the anchoring balloon 309. The second flexible portion 302 of the shaft is substantially covered by an anchoring balloon 309. The third flexible portion 303 has a durometer higher than the durometer of the second and first flexible portions and extends from the proximal end 102 of the catheter 100 to the proximal edges 116, 316 of the anchoring balloon. The flexibility of the carrier catheter decreases progressively from its distal end to its proximal end. Because the portion 301 of the shaft proximate to the directional balloon 307 is flexible, the directional balloon 307 is able to more easily pass through a curved portion of a blood vessel.

In one embodiment as shown in fig. 4a, the distal end of orienting balloon 407 is smooth and contoured to provide smooth movement of the orienting balloon. In another embodiment, the surface of the orienting balloon is coated with a friction reducing coating. In another embodiment, the surface of the orienting balloon may have an undulating profile or other three-dimensional profile (not shown) when inflated to provide a channel for perfusion of blood through the orienting balloon when inflated. In one embodiment shown in fig. 4b, a perfusion lumen 402 is provided to perfuse blood through the anchoring balloon 409 when the anchoring balloon 409 is inflated. In another embodiment as shown in fig. 4c, perfusion lumen 405 is provided to perfuse blood through directional balloon 407 when directional balloon 407 is inflated. In one embodiment shown in fig. 5, there may be several anchoring balloons 501, 502. In another embodiment shown in fig. 6, at least one anchoring balloon may be present in each flexible portion of the shaft, e.g., a first anchoring balloon 601 is present in the first flexible portion 611 and a second anchoring balloon 602 is present in the second flexible portion 612. First anchoring balloon 601 is inflated using first lumen 621 and second anchoring balloon 602 is inflated using second lumen 622, whereby first anchoring balloon 601 may be inflated or deflated independently of inflation or deflation of second anchoring balloon 602, and vice versa. In another embodiment (not shown), a single lumen connects multiple anchoring balloons, whereby all anchoring balloons are inflated or deflated simultaneously. In one embodiment, one or more anchoring balloons may be anchored to the introducer catheter 624, depending on how the orienting balloon 607 is advanced through the vasculature of the patient's body. If the orienting balloon encounters increased resistance, more than one anchoring balloon may be inflated independently. In another embodiment, a directional balloon may be present at the distal edge of the introducer catheter. In another embodiment, the anchoring balloon may be located at a distal portion of the introducer catheter. An anchoring balloon on the introducer catheter may be pressed against the outer surface of the conveyor catheter when inflated to non-slidably anchor the introducer catheter to the conveyor catheter.

In yet another embodiment of the invention shown in fig. 7, the introducer catheter anchored with the conveyor catheter is hydraulically advanced. The system 70 includes a conveyor catheter having a shaft 701, a directional balloon 707 at the distal end of the shaft 701, a hydraulic fluid lumen 721, a hydraulic fluid 722, and a piston 723 movably disposed in the hydraulic fluid lumen and connected to the shaft 701 of the conveyor catheter. The piston forms a seal with the inner surface of the hydraulic fluid lumen. A hydraulic drive, such as a syringe, is used which generates hydraulic pressure on the piston sufficient to advance the shaft 701 of the conveyor conduit. An anchoring balloon 709 attached to the shaft 701 is advanced with the shaft. Upon inflation, anchoring balloon 709 is anchored to an inner surface 725 of introducer catheter 724, and thus advancement of anchoring balloon 709 also advances introducer catheter 724 through the vasculature of the patient. In one embodiment, a method of advancing an introducer catheter a first distance within a vasculature of a patient comprises the steps of: (a) positioning a conveyor conduit within an introducer conduit; (b) inflating the directional balloon; (c) adjusting the position of the conveyor catheter so that the orienting balloon is substantially outside the distal end of the introducer catheter; (d) inflating the anchoring balloon to anchor the conveyor catheter to an inner surface of the lumen of the introducer catheter; (e) hydraulic pressure is applied to the piston to advance the introducer catheter. In another embodiment, after the introducer catheter is advanced a first distance using hydraulic pressure, the introducer catheter is advanced a second distance using the following method: (i) deflating the anchoring balloon; (ii) reducing the hydraulic pressure; (iii) repositioning the conveyor catheter within the lumen of the introducer catheter; (iv) inflating the anchoring balloon to anchor the conveyor catheter to the introducer catheter; and (v) applying the hydraulic pressure again. Steps (i) to (v) may be repeated to continue advancing the catheter system. In one embodiment, the inflation medium comprises a 1:2 mixture of contrast agent and saline.

In one embodiment, the length of the transporter conduit 100 may be about 100cm to about 250 cm. The end use and length of the introducer catheter may determine the length of the conveyor catheter. By way of illustration only, and not limitation, and depending on the physiology of the patient, a cerebral vasculature application may require a transporter catheter having a length of about 100cm to about 150 cm; coronary vasculature applications may require an introducer catheter having a length of about 100cm to about 160 cm; peripheral vasculature applications may require an transporter catheter having a length of about 70cm to about 100 cm; renal vasculature applications may require a length of the conveyor conduit of about 60cm to about 90 cm; hepatic vasculature applications may require a transporter catheter having a length of about 70cm to about 100 cm. In one embodiment, the outer diameter of the shaft 101 of the transporter catheter 100 may be in the range of about 2French to about 12French or more. In another embodiment, the outer diameter of the shaft 101 of the conveyor catheter 100 may be in the range of about 4mm to about 10mm or more. However, the dimensions of the shaft 101 of the conveyor catheter 100 may vary depending on the various applications of the catheter system and the size of the introducer catheter.

In one embodiment, the difference between the outer diameter of the shaft of the conveyor conduit and the inner diameter of the introducer conduit is less than 0.5 mm. In another embodiment, the outer diameter of the shaft of the conveyor conduit is about 0.5mm less than the inner diameter of the introducer conduit. In another embodiment, the outer diameter of the shaft of the conveyor conduit is from about 1mm to about 2mm less than the inner diameter of the introducer conduit. In yet another embodiment, the outer diameter of the shaft of the conveyor conduit is about half the inner diameter of the introducer conduit. In another embodiment, the length of the conveyor conduit may be from about 20cm to about 60 cm. In yet another embodiment, the conveyor conduit may have a short length, for example in the range of about 3cm to about 10 cm. In another embodiment, the length of the conveyor conduit may be in the range of about 10cm to about 300 cm. In one embodiment, the orienting balloon may be located about 3mm from the distal tip of the conveyor catheter. In another embodiment, the gap between the distal end of the anchoring balloon and the proximal end of the orienting balloon may be in the range of about 2-10 mm. In another embodiment, the gap between the distal end of the anchoring balloon and the proximal end of the orienting balloon may be in the range of about 3-5 mm. In one embodiment, the outer diameter of the orienting balloon is substantially the same as the outer diameter of the introducer catheter. In another embodiment, the outer diameter of the orienting balloon is greater than the outer diameter of the introducer catheter. In one embodiment, the orienting balloon is compliant. In another embodiment, the anchoring balloon is non-compliant. In yet another embodiment, the orienting balloon is semi-compliant.

The distal end 103 of the shaft 101 may or may not be tapered. In one embodiment, the shaft 101 may have a tapered shape, with the proximal end 102 having a larger diameter than the distal end 103. The end use and inner diameter of the introducer catheter may determine the outer diameter of the shaft 101. In one embodiment, the inner diameter of the shaft 101 may be in a range of about 1French to about 3French or greater. If the shaft 101 were to receive the guidewire 108, the inner diameter of the shaft would need to be scaled accordingly. In one embodiment, a guidewire up to 1.4French in diameter may be used. In another embodiment, the guidewire may not be used in conjunction with a conveyor catheter, and the conveyor catheter may not have a lumen 105 for the guidewire. In one embodiment, the transporter catheter may deliver the introducer catheter over a guidewire to a desired location. In another embodiment, the transporter catheter may deliver the introducer catheter to a desired location without the use of a guidewire. After positioning the introducer catheter, if a stylet(s) is present, it can be removed and then the orienting and anchoring balloons can be deflated by hand-held syringe or other means. In one embodiment, the conveyor catheter is configured to track over a 0.009-0.014 "guidewire. In another embodiment, the conveyor catheter may have a central lumen capable of receiving guidewires of various diameters (e.g., guidewires having diameters in the range of 0.010 "to 0.065"). In one embodiment, the conveyor conduit may be configured in a "rapid exchange" configuration. In another embodiment, the carrier catheter may be configured in an "over the wire" configuration. In another embodiment, the conveyor catheter may not include a directional balloon, and may include at least one anchoring balloon and/or may include at least one mechanical connector, the anchoring balloon and/or mechanical connector being located at the distal end of the conveyor catheter. The at least one balloon and/or the at least one mechanical connector anchor the distal end of the conveyor catheter to the external catheter. In one embodiment, the distal end of the carrier catheter is anchored to the distal end of the outer catheter. In another embodiment, the at least one anchoring balloon and/or the at least one mechanical connector are located at the distal portion of the conveyor catheter. In yet another embodiment, the distal portion of the transporter catheter is anchored to the distal portion of the outer catheter.

The materials used for shaft 101, lumens 104, 105, and 106, orienting balloon 107 may include any one or more of the following additives. By way of illustration only and not limitation, such additives may include radiopaque fillers, slip additives, and hydrophilic coatings. In one embodiment, the silicon provides a hydrophilic coating. In another embodiment, the material for the shaft 101 includes a particulate radiopaque filler material. In one embodiment, the anchoring mechanism that non-slidably anchors the conveyor catheter to the outer catheter is a friction-based mechanism between the outer surface of the conveyor catheter and the inner surface of the outer catheter. In another embodiment, the anchoring balloon may be made of and/or coated with a material that provides frictional resistance to reduce slippage. In one embodiment, the anchoring balloon may be made of polyurethane. In another embodiment, the anchoring balloon may have serrations 801 as shown in fig. 8a and/or raised protrusions 802 as shown in fig. 8b to enhance the anchoring ability of the anchoring balloon to the interior of the introducer sheath after inflation of the anchoring balloon. The serrations and/or raised protrusions may have a spiral shape 801 as shown in fig. 8a, a linear shape 802 as shown in fig. 8b, and other shapes, for example, see a donut shape 803 (see fig. 8c) or a cross-hatched shape 804 (see fig. 8 d). The projections may have inserts, such as filaments. The filaments or filament sections may be made of a variety of materials and may each be made of the same material or materials with similar material properties or of different materials with different properties. Such wires or wire segments may be formed of stainless steel, for example. The material of the filaments may be harder than the material forming the balloon wall. In another embodiment, the filaments are made of nitinol. The protrusions enhance the anchoring ability of the anchoring balloon to the inner surface of an external catheter (e.g., an introducer catheter) by thickening the outer surface of the anchoring balloon and anchoring the outer surface of the anchoring balloon to the inner surface of the introducer catheter. The filaments or filament segments forming the protrusions may also have any cross-sectional geometry including, for example, circular, square or triangular, and different protrusions may have different cross-sectional shapes. The rounded shape and/or smooth edges may help prevent the filaments or filament segments forming the protrusions from piercing the wall of the anchoring balloon. In one embodiment, the wire or wire segment may be hollow to allow blood to pass through, thereby preventing blood blockage when the anchoring balloon is inflated. In another embodiment, the inner surface of the outer catheter may be configured at the distal portion of the outer catheter to enhance frictional anchoring capability, for example, the inner surface of the outer catheter at the distal portion may have a layer of material with a higher coefficient of friction or may have knurling or serrations, or may be otherwise treated to increase frictional resistance in that portion of the inner surface of the outer catheter.

In one embodiment, the wire or wire segment comprises a radiopaque material (or a homogeneous material or a material that is radiopaque but provided with a radiopaque coating), and is therefore visible under fluoroscopy. Making the protrusions visible may also allow the clinician to better discern the location and orientation of the anchoring balloon, as well as the location of the anchoring balloon prior to inflating and anchoring the balloon to the inner surface of the introducer catheter. In another embodiment, the wall of the anchoring balloon may include radiopaque particles.

In one embodiment, at least one mechanical connector is used to connect and anchor the conveyor catheter and the introducer catheter. In another embodiment, the carrier conduit includes a mechanical connector that anchors the carrier conduit to an inner surface of the introducer conduit. In yet another embodiment, the carrier catheter includes a mechanical connector to anchor the carrier catheter to the introducer catheter at or near the distal edge of the introducer catheter. In another embodiment, the carrier catheter and/or introducer catheter includes at least one mechanical connector in a distal portion of the carrier catheter and/or a distal portion of the introducer catheter. In one embodiment, a handle at the proximal end of the carrier catheter may be used to engage a mechanical connector, thereby enabling the carrier catheter to be anchored to the introducer catheter. A handle at the proximal end of the feeder catheter may also be used to disengage the mechanical connector, allowing the feeder catheter to be removed from the introducer catheter. In another embodiment, a handle at the proximal end of the introducer catheter can be used to engage or disengage the mechanical connector. In one embodiment, the mechanical connector is a circular cage comprised of a matrix of round or flat wires, wherein the diameter of the cage may be mechanically increased or decreased. In another embodiment, the diameter of the cage may be increased or decreased, for example, by rotating a handle at the proximal end of the transporter conduit, whereby when the handle is rotated in one direction, the cage is twisted to open and increase its diameter, and when the handle is rotated in the other direction, the cage is twisted to close and decrease its diameter. The cage increases in diameter until it presses against the inner surface of the introducer catheter to anchor the conveyor catheter to the introducer catheter. In another embodiment, a mechanical connector may be located on the introducer catheter and the mechanical connector engages the conveyor catheter, e.g., pressing or locking against the conveyor catheter, to anchor the introducer catheter to the conveyor catheter.

In operation, the conveyor catheter and external catheter may be advanced from various arterial access sites, such as the femoral, radial, brachial, axillary, and carotid arteries, to gain percutaneous or surgical access to the arterial circulation. In one embodiment, once access is obtained, the device is advanced from the access site via the aorta to the desired target location for diagnostic or interventional procedures. Introducing the catheter directly through the arteriotomy increases the likelihood that the catheter edges will abrade the inner arterial wall (also called the intima). To reduce the risk of such possible interaction, a guidewire is typically first advanced through the arteriotomy. Guidewires are typically soft-tipped, lower profile, flexible objects, e.g., with atraumatic tips. The placement of the guidewire and the introduction of the catheter over the guidewire centers the catheter in the arterial lumen and reduces the risk of the catheter abrading the inner arterial wall. Although the risk of intima of the arterial circulation is reduced due to the placement and advancement over the wire, there is still a risk of abrasion of the arterial vessel inner wall due to catheter draping (overhang), due to the fact that the diameter of the guide wire is usually much smaller compared to the catheter. This abrasive effect of the catheter (commonly referred to as the "razor effect") can lead to the elements falling off the inner wall of the artery, for example leading to atherosclerotic and other debris. Released atherosclerotic and other debris may follow the arterial circulation and may enter a small distal branch based on the size of such debris. This event may lead to tissue death or necrosis, which may lead to permanent organ dysfunction, including ischemic necrosis of the bowel due to atherosclerotic embolic events, acute kidney injury due to embolic-like events, and cerebrovascular events due to the release of atheroma that may result from the passage of a catheter through the ascending aorta and aortic arch. Embodiments of the present invention that include a directional balloon generally provide a draping solution, thereby reducing the likelihood of transition, and thus reducing the razor effect and reducing the risk of embolic events that may result from catheter transport.

In operation as shown in fig. 9, orienting balloon 907 orients and steers the catheter system including introducer catheter 924 and conveyor catheter 901 through the curve of vasculature 931 within the patient. The directional balloon 907 protrudes out of the introducer catheter 924. In one embodiment, about 50% of the directional balloon protrudes out of the introducer catheter 924. In another embodiment, more than 50% of the directional balloon 907 protrudes out of the introducer catheter. In yet another embodiment, about 80% of the directional balloon 907 protrudes out of the introducer catheter 924. In another embodiment, less than 50% of the directional balloon 907 protrudes out of the introducer catheter 924. In one embodiment, the directional balloon may be inflated using a pressure of about 2 atmospheres to about 10 atmospheres or more. In another embodiment, the directional balloon is inflatable to have a pressure in the range of 12-15 atmospheres. In another embodiment, the directional balloon is inflated using a pressure of about 4 atmospheres. In one embodiment, the diameter of the protruding portion of the orienting balloon protruding from the introducer catheter may be greater than the outer diameter of the introducer catheter, thereby substantially reducing or eliminating potential shaving effects at the edge of the introducer catheter. In one embodiment, there may be two directional balloons. In another embodiment, the diameters of the two orienting balloons may be the same. In yet another embodiment, the diameter of the distally oriented balloon may be smaller or larger than the diameter of the proximally oriented balloon. In one embodiment, the proximally-directed balloon is partially inside and partially protruding outside the introducer catheter, and the distally-directed balloon is completely outside the introducer catheter. In some embodiments, there may be more than two orienting balloons. In one embodiment, the diameter of the directional balloon may taper from the proximally directional balloon to the distally directional balloon located near the tip of the introducer catheter. In one embodiment, the orienting balloon is coated and/or shaped to minimize friction between the orienting balloon and the inner surface of the patient's vasculature. Upon expansion, the at least one orienting balloon engages an inner surface of the patient's vasculature. In one embodiment, the orienting balloon slidably engages an inner surface of the patient's vasculature when the balloon is fully expanded. In another embodiment, the orienting balloon slidably engages an inner surface of the patient's vasculature when the balloon is partially expanded. In embodiments where there is more than one orienting balloon, the first orienting balloon may engage an interior surface of the vasculature of the patient and the second orientation may not engage an interior surface of the vasculature of the patient. In another embodiment, the proximally-directed balloon that protrudes outside of the introducer catheter engages an interior surface of the patient's vasculature when the proximally-directed balloon is fully expanded, and the distally-directed balloon does not engage the interior surface of the patient's vasculature when fully expanded. Anchoring balloon 909 anchors the shaft of the conveyor catheter 901 to the inner surface of the lumen of the introducer catheter 924. In one embodiment, a guidewire 908 may be present. In another embodiment, the segment 911 between the anchoring balloon 909 and the orienting balloon 907 may be more flexible than the segment 901 of the conveyor catheter. The catheter system can be advanced by pushing and/or twisting the introducer catheter 924 or the conveyor catheter 901, or both. If the catheter system is advanced by pushing on the introducer catheter, the wall of the introducer catheter should have sufficient axial strength to be pushed through the patient's vasculature by the force applied at its proximal end ("pushability"). It is also desirable for the introducer catheter to be able to transmit torque applied at the proximal end to the distal end along the length of the shaft ("torqueability"). The introducer catheter should also be sufficiently flexible to substantially conform to the vasculature of the patient and resist kinking as it is pushed and/or twisted through and conforms to the vasculature of the patient.

The walls of the introducer catheter 924 that are advanced by pushing the introducer catheter are thick, and increasing the aperture of an introducer catheter with a given overall diameter requires the use of thinner walls. As catheters are used in smaller and smaller blood vessels and body lumens, there is an increasing need to use introducer catheters having smaller wall thicknesses. However, thin-walled introducer catheters that are pushed through the vasculature of a patient are more likely to self-collapse or kink when a pushing force and/or torque is applied at their proximal ends. On the other hand, if the introducer catheter 924 is pulled through the patient's vasculature by the anchor balloon 909 of the conveyor catheter, the wall of the introducer catheter 924 may be relatively thin. Thin walls may be used because pulling tension is applied to the walls of the introducer catheter 924 as the introducer catheter 924 is pulled through the patient's vasculature 931. The tension has a stretching effect on the wall of the introducer catheter and prevents kinking of the wall of the introducer catheter 924. On the other hand, if the introducer catheter 924 is pushed through the patient's vasculature, a compressive force is applied to the wall of the introducer catheter 924. If the introducer catheter 924 experiences resistance and is pushed back from the lumen of the patient, the compressive force can cause the walls of the introducer catheter 924 to kink. In one embodiment, pushing the transporter conduit to advance the external conduit to a desired location in the patient's body substantially results in pulling the external conduit to the desired location. In one embodiment, the thickness of the wall of the introducer conduit 924 is less than the thickness of the wall of the conveyor conduit 901. In another embodiment, the walls of the introducer conduit 924 are more flexible than the walls of the conveyor conduit 901. In another embodiment, the wall of the conveyor duct 901 includes a wire structure to increase the stiffness of the wall of the conveyor duct. In another embodiment, the wall of the introducer catheter 924 does not include a wire structure. In yet another embodiment, the introducer catheter 924 in the proximal portion of the introducer catheter may be more flexible than the conveyor catheter 901 in the proximal portion of the conveyor catheter. In one embodiment, the wall of the introducer conduit 924 is less than 0.2mm thick. In another embodiment, the wall of the introducer conduit 924 is less than 0.1mm thick. In yet another embodiment, the wall of the introducer conduit 924 is less than 0.5mm thick. In one embodiment, the outer wall of the introducer catheter 924 is provided with a hydrophilic coating to reduce friction between the outer wall of the introducer catheter 924 and the inner wall of the lumen 931 through which the introducer catheter is advanced.

Fig. 10a is a schematic illustration of the forces acting on the introducer catheter when the user pushes the introducer catheter in direction 133 at the proximal end of introducer catheter 124 using handle 132. The pushing force 151 on the wall of the introducer catheter has a horizontal component 153 that advances the introducer catheter 124 through the vasculature 131 of the patient's body and a vertical component 152 that presses the wall of the introducer catheter 124 against the wall of the vasculature 131. Because the component 152 is directed toward the wall of the vasculature 131, the component 152 adds frictional resistance and resistance to the introducer catheter as it is advanced through the vasculature. Due to the additional frictional resistance, a greater pushing force is required, requiring thicker walls for the introducer catheter so that the introducer catheter does not collapse or kink. The greater thrust also results in additional frictional resistance due to the greater vertical component 152. The total frictional resistance depends on the contact area between the introducer catheter and the vascular system and thus partly on the length of the introducer catheter inserted into the vascular system of the patient's body. Due to the combination of frictional resistance and increased pushing force, the length over which the introducer catheter can be pushed within the vasculature may be limited.

Fig. 10b is a schematic illustration of the forces acting on the introducer catheter as it is pulled by the anchoring balloon of the conveyor catheter when the user pushes the conveyor catheter to advance the introducer catheter. As the user pushes the conveyor catheter 201 in direction 233 and through it pushes its anchoring balloon 209, the anchoring balloon exerts a pulling force 251 on the wall of the introducer catheter 124. The pulling force 251 on the wall of the introducer catheter has a horizontal component 253 that advances the introducer catheter 124 through the vasculature 131 of the patient's body and a vertical component 252 that pulls the wall of the introducer catheter 124 away from the wall of the vasculature 131. Because the component 252 is directed away from the walls of the vasculature, the component 252 reduces frictional resistance and counter-force on the introducer catheter as it is advanced through the vasculature. Thus, less thrust force is required on the transporter catheter to advance the catheter system through the vasculature. Furthermore, since the walls of the introducer catheter are subjected to a pulling force at the distal end (rather than a pushing force at the proximal end), the likelihood of kinking of the walls of the introducer catheter is reduced and thinner walls can be used for the introducer catheter. After the introducer catheter is positioned at the desired location, the conveyor catheter is removed. Thus, for a given outer diameter of the introducer catheter and by advancing the introducer catheter using the transporter catheter (or advancing any other external catheter, such as a sheath, guide catheter, or mother catheter), the user may use an introducer catheter with thinner walls, thereby providing a larger diameter of its lumen. In one embodiment, the transporter conduit may be used to pull the introducer conduit through tortuous arteries (including the celiac artery and the mesenteric artery). In another embodiment, a catheter system including a delivery catheter may be used for revascularization and de-vascularization in the cerebral circulation. In yet another embodiment, a catheter system including a transporter catheter may be used to cannulate the central coronary vein when implanting a CRT-D device or other device. In one embodiment, the catheter system including the transporter conduit may be used for remote telerobotic procedures, such as stroke management. In another embodiment, a system including a conveyor catheter may be used to assist in the manipulation and positioning of an endoscopic tube or colonoscope tube within the patient's digestive tract.

In another embodiment (see fig. 11 and 12) comprising a parent catheter 166 and an internal support catheter (child or childhood catheter) 165 advanced over a guidewire 168, the internal support catheter 165 is advanced by placing a conveyor catheter 161 within the lumen of the internal support catheter 165, where the conveyor catheter has a directional balloon 167 protruding from the tip of the internal support catheter and another balloon 169 within the lumen of the internal catheter 165 that provides anchoring. Using the multi-balloon transporter catheter 161 to advance the inner catheter 165, a double balloon catheter composite can be advanced through the unfavorable arterial lumen, across the stenosis 162. After the internal support catheter has been successfully placed across the stenosis 162, the conveyor catheter is withdrawn after the directional and anchoring balloons are deflated. A stent 164 (see fig. 13) or other hardware may then be placed through the internal support catheter 165 distal to the stenosis 162 or at another preferred location. The internal support catheter is then withdrawn and the stent 164 is then positioned, typically by pulling the stent 164 to the site of interest and deploying the stent 164 (fig. 13). In one embodiment, at least one aperture may be provided in the structure of the internal support conduit to allow blood to perfuse the internal support conduit from outside the internal support conduit. In one embodiment, the conveyor catheter is inserted into the outer catheter while the orienting balloon remains partially extended out of the tip of the outer catheter. The directional balloon is then inflated with a fluid at sufficient pressure to reach a certain diameter. In one embodiment, the diameter of the inflated orienting balloon is at least equal to the inner diameter of the outer catheter tip. In another embodiment, the diameter of the protruding portion of the orienting balloon is at least equal to the outer diameter of the outer catheter tip. In yet another embodiment, the protruding portion of the orienting balloon has a diameter greater than the outer diameter of the outer catheter tip. The guidewire may be placed through the orienting balloon before, during, or after inflation.

The inner support catheter may include a hydrophilic coating to reduce friction between the arterial lumen and the outer surface of the inner support catheter. The walls of the internal support catheter can be made thin, whereby the internal lumen of the support catheter has a large diameter and the external dimensions of the internal support catheter conform to the geometry of the coronary artery or other vessel. Because the conveyor conduit is used to advance the inner support conduit, the inner support conduit does not require as much structure (e.g., greater wall thickness) to transmit longitudinal axial forces.

In one embodiment, the conveyor catheter has at least one balloon that functions as both a directional balloon and an anchoring balloon. The conveyor conduit comprises: a shaft comprising a proximal end and a distal end; at least one balloon positioned adjacent the distal end of the shaft, the at least one balloon (see fig. 14 a-14 d) comprising a distal portion 855 and a proximal portion 856; the distal portion 855 of the at least one balloon has a surface when inflated that is configured to smoothly move the transporter catheter through the patient's vasculature, and the proximal portion 856 of the at least one balloon has a surface when inflated that is configured to anchor the transporter catheter to the outer catheter 224 (see fig. 15); wherein, in operation, the conveyor catheter is located within the lumen 226 of the outer catheter 224 and the proximal portion 856 of the at least one balloon, when inflated, presses against the inner surface 857 of the lumen of the outer catheter, anchoring the conveyor catheter 859 near the distal end of the conveyor catheter to the outer catheter 224 near the distal end of the outer catheter (see fig. 15); and, thereafter, when the transporter catheter is pushed and/or twisted to advance the external catheter to a desired location in the patient's vasculature, the transporter catheter actually pulls the external catheter to the desired location in the patient's vasculature. In another embodiment, the interface 858 between the distal and proximal portions of at least one balloon includes radiopaque markings. In yet another embodiment, the distal portion of the at least one balloon is smooth and contoured to assist in smooth advancement of the transporter catheter through the vasculature of the patient's body. In one embodiment, the surface of the distal portion of at least one balloon is coated with a friction-reducing coating. In another embodiment, when the at least one balloon is subjected to increased resistance within the patient's vasculature, a proximal portion of the at least one balloon reduces the carrier catheter from sliding or pushing back into the lumen of the outer catheter after anchoring to the inner surface of the lumen of the outer catheter. In yet another embodiment, a surface of the distal portion of the at least one balloon includes a channel for perfusing blood through the at least one balloon after the at least one balloon is inflated.

In one embodiment (see fig. 16), the diameter of the distal portion 860 of the at least one balloon is larger than the outer diameter of the outer catheter when inflated, thereby substantially reducing or eliminating potential shaving effects of the edges of the outer catheter. In another embodiment, the proximal portion of the at least one balloon anchors the conveyor catheter to the outer catheter using a friction-based mechanism between an outer surface of the proximal portion of the at least one balloon and an inner surface of the lumen of the outer catheter. In one embodiment, the friction-based mechanism includes at least serrations 851 (fig. 14a) and/or raised protrusions 852 (fig. 14b), wherein the serrations and/or raised protrusions have a shape that includes a spiral 851 (fig. 14a), a straight shape 852 (fig. 14b), a circle 853 (fig. 14c), a cross 854 (fig. 14d), or a combination thereof. In another embodiment, the friction-based mechanism includes at least one outer layer at least partially covering an outer surface of the proximal portion of the at least one balloon in contact with an inner surface of the lumen of the outer catheter, the outer layer including a material that provides a higher frictional resistance. In one embodiment, the outer layer may comprise an etched polymeric material, such as an etched Polytetrafluoroethylene (PTFE) layer. In another embodiment, a layer of interlaced and/or braided filaments may be embedded on the outer surface of the balloon, or the filaments may be glued or otherwise attached to the outer surface of the at least one balloon.

In one embodiment, the conveyor catheter includes at least two balloons (see fig. 17). A first balloon 867 is located near the distal end of the conveyor catheter, the first balloon 867 having a distal portion 855 that facilitates orientation and manipulation of the conveyor catheter and a proximal portion 856 that anchors the conveyor catheter to the inner surface of the outer catheter 224. The second balloon 869 is an anchoring balloon and is located adjacent the first balloon 867. In one embodiment of a method of advancing the outer catheter 224, both the first and second balloons may be inflated separately and independently to anchor the conveyor catheter to the outer catheter. Next, the transporter catheter is pushed and/or twisted to advance the external catheter to substantially near the treatment location in the patient's frontal vasculature. Subsequently, the second balloon may be deflated and, upon further pushing and/or twisting of the conveyor catheter, the first balloon pulls the distal end of the outer catheter to or beyond the treatment site. Subsequently, the first balloon may be deflated and the conveyor catheter removed from inside the outer catheter, and the treatment system may then be advanced inside the outer catheter to a location at or beyond the treatment site. In another embodiment of the method, the first and second balloons may be deflated and the conveyor catheter may be removed after the outer catheter is advanced to the desired location.

Fig. 18a depicts a cross-sectional view of an embodiment of the shaft of the conveyor catheter as shown in the embodiment depicted in fig. 15. The conveyor conduit is comprised of a tubular polymer liner 182, a torque transfer layer 184, a core 186 comprised of a melt-processed polymer, and a heat shrink layer 188. Lumen 191 provides for passage of a guidewire and lumen 192 provides for inflation or deflation of a directional balloon. FIG. 18b depicts a cross-sectional view of an embodiment of the shaft of the conveyor conduit as shown in the embodiment depicted in FIG. 17. Lumen 193 is provided for inflating or deflating anchoring balloon 869.

In one embodiment, the conveyor conduit is steerable using a wire. In another embodiment, the pull wire comprises at least one flat wire 190, the at least one flat wire 190 being disposed longitudinally along the length of the conveyor conduit (see fig. 18c and 18 d). The flat wire 190 typically has a rectangular cross-section, but the cross-section of the wire need not be perfectly rectangular. In another embodiment, the cross-sectional shape of the wire may be oval or circular. The conveyor catheter 100 (see fig. 1) may include an elongated pull wire that extends through the pull wire lumen of the shaft 101 of the conveyor catheter 100 and terminates within the distal portion of the shaft. In one embodiment, the pull wire has a proximal end operably connected to the handle assembly and a distal end anchored to the distal portion of the transporter conduit. In another embodiment as shown in fig. 19, the steerable conveyor catheter may include a wiredrawing anchoring ring or steering ring 195 that mechanically couples the distal end of the wiredrawing to the distal portion of the conveyor catheter. In one embodiment, the steering ring 195 may be located at or near the distal end 115 of the anchoring balloon 109. In another embodiment, the diverter ring 195 may be located below the anchoring balloon 109. In yet another embodiment, the steering ring 195 may be located near the proximal or distal end of the orienting balloon 107. In another embodiment, there may be more than one steering ring. In one embodiment, the torque transfer layer 184 may be disposed between the inner liner 182 and the pull wire 190. In another embodiment, a torque transfer layer may be disposed between the wiredrawing 190 and the heat shrink layer 188. In another embodiment, the heat shrink layer may not be present. In one embodiment, the pull wire 190 may be covered with a lubricious material prior to placement within the conveyor conduit. The lubricating material includes silicone and other lubricating materials. In another embodiment, the wire 190 may be smooth and coated with a lubricious layer. In one embodiment, the wire is made of stainless steel. In another embodiment, more than one wire may be used. In another embodiment, two wires may be used and spaced at an angle of 180 degrees apart (see, e.g., fig. 18 d). In one embodiment, the pull wire 190 is connected to at least one anchoring ring 195 located near the distal end of the introducer (see fig. 19). The proximal end of the pull wire 190 is operably connected to a steering mechanism (not shown) that allows steering of the transporter catheter 100 during operation. In one embodiment, the wiredrawing may be contained within a lumen-forming polymer tube 196.

In one embodiment, the liner 182 is a polymeric material, such as Polytetrafluoroethylene (PTFE) or etched PTFE. The inner liner 182 may also be made from other melt-processing polymers including, but not limited to, polyether block amide, nylon, and other thermoplastic elastomers. Once this elastomer is Pebax (Pebax is a registered trademark and manufactured by Arkema, Inc.). Pebax of various hardnesses may also be used, including but not limited to Pebax 30D to Pebax 70D. In one embodiment, the core 186 of the shaft is made of extruded Pebax or PTFE tubing. The melt processed polymer of the core 186 occupies the plurality of voids of the wire mesh in the torque transmitting layer. The core 186 may also be made from other melt-processed polymers having different hardnesses, including but not limited to etched PTFE, polyether block amide, nylon, and other thermoplastic elastomers. The core 186 may also include more than one layer, including, for example, two or more melt processed polymer tubes (see fig. 19).

In one embodiment, a method of intravascular treatment using a transporter catheter includes the steps of: (i) assembling a system comprising a conveyor catheter and an outer catheter, the conveyor catheter comprising a shaft having at least a first wall, a proximal end, a distal end and at least one internal channel for a guidewire, the outer catheter comprising a substantially cylindrical lumen having a second wall, a proximal end and a distal end, the conveyor catheter extending within the lumen of the outer catheter, wherein the distal end of the conveyor catheter is substantially aligned with the distal end of the outer catheter, an anchoring mechanism being displaced in operative coupling with the conveyor catheter and/or the outer catheter, whereby the anchoring mechanism anchors at least the distal portion of the conveyor catheter to at least the distal portion of the outer catheter, the anchoring mechanism controllably actuating anchoring or removal for anchoring the conveyor catheter to the outer catheter; (ii) extending a guidewire along the internal passageway of the conveyor catheter, wherein a proximal end of the guidewire extends beyond a proximal end of the conveyor catheter and a distal end of the guidewire extends beyond a distal end of the conveyor catheter; (iii) pushing a distal end of the guidewire to a desired location in a vessel of interest at a treatment site; (iv) controlling the anchoring mechanism to anchor at least the distal portion of the outer catheter to at least a distal portion of the conveyor catheter; (v) advancing the system by pushing and/or twisting at least the transporter catheter along the guidewire toward the treatment site until the system is aligned with or beyond the treatment site; (vi) actuating the anchoring mechanism to remove the anchoring hold between the transporter catheter and the outer catheter; (vii) removing the conveyor conduit from within the outer conduit; and (viii) advancing the treatment system within the outer catheter to a position at or beyond the treatment site.

In one embodiment, the conveyor conduit 100 is manufactured by an extrusion process. Since extrusion processes are well known in the art, the general process is not discussed in detail herein. Typically, the extrusion process begins with heating the polymer until molten. The molten polymer is then forced under pressure through an extruder die core (extrusion tip) and an extrusion die (extrusion die). As the molten polymer exits the extruder core and the extrusion die, it is cooled. A typical cooling method employs a water bath. The cooling step solidifies the device to the desired dimensions.

Shaft 101 and lumens 104, 105 and 106 may be fabricated using any commercially available catheter material. Materials may include, but are not limited to, polyethylene, polyamide, and polyurethane. Polyolefins may also be used, for example: polypropylene; polyesters, including polyamides and polyethylene terephthalate; fluorine-based polymers including PTFE (polytetrafluoroethylene); PEEK (polyetheretherketone); a polyimide; synthetic resin elastomers including olefin elastomers (e.g., polyethylene elastomers and polypropylene elastomers), polyamide elastomers, styrene elastomers (e.g., styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-ethylenebutylene-styrene copolymers); polyurethanes, polyurethane-based elastomers, and fluorine-based elastomers; synthetic rubbers, including polyurethane rubbers, silicone rubbers, and butadiene rubbers. The material selected will depend on the end use of the catheter, the size of the vessel to be accessed, and/or whether one or more stylets will be used to provide assistance during insertion and advancement of the catheter system. The desired end use will determine the degree of stiffness, flexibility, strength and/or smoothness of the material(s) used. The orienting balloon 107 and anchoring balloon 109 may be manufactured using any commercially available balloon material. Materials include, but are not limited to, latex, silicone, ethyl vinyl acetate (ethylvinylacetate), and polyurethane.

It will be appreciated that several of the above-disclosed and other features and functions, or alternatives or variations thereof, may be desirably combined into many other different systems or applications. Also, it will be appreciated that various substitutions, derivations, modifications, changes or improvements therein or thereto may be subsequently made by those skilled in the art, which are also intended to be encompassed by the appended claims.

In the description above, for purposes of explanation, certain requirements and certain details have been included in order to provide an understanding of the embodiments. It will be apparent, however, to one skilled in the art that one or more other embodiments may be practiced without some of the requirements or details. The particular embodiments described are not intended to be limiting of the invention but rather are merely illustrative of the invention. The scope of the invention should not be determined by the specific examples provided above. In other instances, well-known structures, devices, and operations have been shown in block diagram form or not in detail in order to avoid obscuring the understanding of the description. Where appropriate, reference numerals or terminal portions of reference numerals in the drawings have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.

It should also be understood that reference throughout this specification to "one embodiment," "an embodiment," "one or more embodiments," or "different embodiments," for example, means that a particular feature may be included in the practice of the invention. Similarly, it should be appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects may lie in less than all features of a single disclosed embodiment. In another case, the inventive aspects can include combinations of the embodiments described herein or combinations of less than all of the aspects described in the combinations of embodiments.

Claims (15)

1. A conveyor catheter configured to be positioned within a lumen of an external catheter, the conveyor catheter comprising:

a shaft comprising a proximal end, a distal end, at least one orienting balloon, and at least one anchoring balloon;

the at least one orienting balloon is positioned on the shaft adjacent the distal end of the shaft, the at least one orienting balloon configured to slidably engage an inner surface of a vasculature of a patient;

the at least one anchoring balloon is located on the shaft between the at least one orienting balloon and the proximal end of the shaft, the at least one anchoring balloon configured to non-slidably anchor the conveyor catheter to the outer catheter by pressing against an inner surface of the lumen of the outer catheter; and

the shaft is configured to be pushed and/or twisted to advance and steer the external catheter through the patient's vasculature.

2. A conveyor catheter as in claim 1 further comprising a guidewire and wherein the shaft includes at least one internal channel for the guidewire.

3. The conveyor catheter of claim 1, wherein the at least one orienting balloon comprises a proximal portion and a distal portion, the distal portion of the at least one orienting balloon being located outside of the distal end of the outer catheter and the proximal portion of the at least one orienting balloon being located inside of the distal end of the outer catheter.

4. The conveyor catheter of claim 1, wherein the at least one orienting balloon comprises a proximal portion and a distal portion, the distal portion of the at least one orienting balloon being contoured to assist in smooth advancement of the outer catheter through the patient's vasculature.

5. The conveyor catheter of claim 1 wherein the at least one orienting balloon includes a proximal portion and a distal portion, at least a surface of the distal portion of the at least one orienting balloon being coated with a friction reducing coating.

6. The conveyor catheter of claim 1, wherein the at least one orienting balloon comprises a proximal portion and a distal portion, the distal portion of the at least one orienting balloon having a diameter about equal to or greater than an outer diameter of the outer catheter.

7. The conveyor duct of claim 1 wherein said conveyor duct is steerable using at least one pull wire disposed longitudinally along the length of said conveyor duct.

8. The conveyor catheter of claim 7, further comprising at least one steering ring mechanically coupling the distal end of the at least one pull wire to the distal portion of the conveyor catheter, wherein the steering ring is disposed on the shaft at a location selected from the group consisting of: (a) at or near the distal end of the anchoring balloon, (b) below the anchoring balloon, (c) near the proximal end of the orienting balloon, and (d) near the distal end of the orienting balloon.

9. The conveyor catheter of claim 1, further comprising a stiffening stylet to stiffen the shaft.

10. Conveyor conduit according to claim 1, wherein the shaft comprises a torque transfer layer comprising helical coils and/or a braided matrix.

11. The conveyor catheter of claim 1, wherein the shaft comprises a plurality of segments having varying stiffnesses, and wherein a stiffness of the varying stiffnesses at the proximal end of the shaft is greater than a stiffness of the varying stiffnesses at the distal end of the shaft.

12. The conveyor catheter of claim 1, wherein the shaft comprises at least an inner layer and an outer layer, the outer layer comprising a braided wire assembly formed by braiding a plurality of flat wires, round wires, or a combination thereof.

13. The conveyor catheter of claim 1, wherein the at least one anchoring balloon comprises a coating and/or material configured to provide frictional resistance to reduce slippage, or a friction-based mechanism is used between an outer surface of the at least one anchoring balloon and the inner surface of the lumen of the outer catheter.

14. The conveyor catheter of claim 1, wherein said shaft is tapered and the diameter of said proximal end of said shaft is greater than the diameter of said distal end of said shaft.

15. The transporter catheter of claim 1, further comprising at least one radiopaque marker, wherein the at least one radiopaque marker is disposed at one or more locations on the transporter catheter selected from the group consisting of: the at least one orienting balloon, the at least one anchoring balloon, a length of the shaft, the distal end of the shaft, a region proximate a leading end portion of the orienting balloon.

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